At the end of the 21st century, cities have fallen into ruin, the air is toxic and the sun is obscured by pollution. Quinto is on the run from his malevolent master and seeking sanctuary in the fabled City in the Sky. Ai, a malfunctioning sex-worker android, awaits deactivation locked in a squalid hotel. Through an error at check-in at the hotel, Quinto meets Ai.